Use Analysis

Updated on:
November 13, 2023

Many people don’t realize that not all water filters are the same. They are all designed to target certain contaminants, and it’s important you get a filter that is going to tackle what’s actually in your water.

For the most part, manufacturers are pretty good at identifying what their products can and can’t do. But they do also like to position their products as “good for everyone.” 

The first step in all our product reviews is to sort the products from our initial list based on their specific use. Mainly, this means looking at the contaminants they are designed to filter and removing anything that’s not specifically designed to handle the water quality issue we’re trying to address.

The biggest thing to consider is the type of water supply in question, but there are other factors as well. 

Well Water vs. City Water

The very first thing we want to check is if the filter in question is better designed for city water or well water. 

City water is public water cleaned and distributed by local authorities. It’s treated at a facility somewhere in your area and then sent out through city pipes until it gets to your home. 

The benefit of city water is that cities are held to certain standards set by the EPA to ensure the water that reaches your home is safe and clean to drink. It’s also tested regularly to instill confidence and promote transparency, and if the system is compromised for whatever reason, you’ll be informed and given alternatives. 

The downside to city water is that you have to pay for it. That’s where your monthly water bill comes from. 

Well water comes from the ground directly below your home. A well is basically a big hole that gives you access to water buried deep underground. A well pump draws water up into a pressure tank which is where the water that runs through your taps comes from. 

The big advantage to well water is that it is free once the well is drilled. No monthly water bills. The drawback, however, is that it’s not treated. Lots of stuff can get into your water, and it’s your responsibility as a well owner to test your water supply. 

Since the conditions in the ground surrounding your well water source are changing all the time, it’s recommended you test your water once a year to ensure its safety.

Common Contaminants in City Water

You might be thinking that because city water is regularly tested and treated, it’s not contaminated. But that simply isn’t true. 

According to Jean Goddard, PhD, at Simple Lab, one of our trusted partners, ”There are many regulated contaminants in the US, but these standards are designed to balance between what’s financially feasible and the public health benefits of treatment. This means we accept a certain level of health risk for many contaminants in drinking water. Some groups, like children, are more affected than others even if the levels are ‘within regulation.’ We recommend checking to see if the levels of regulated contaminants are within both MCL and MCLG to fully understand your health risks.”

When a water supply meets federal guidelines, it does not mean its contaminant-free. It simply means the levels of these contaminants are below what the EPA considers both safe and economically reasonable. 

Here are some common contaminants that may be present to some degree in your municipal water supply: 

  • Chlorine and chloramine: These are added to water supplies at the treatment facility to kill bacteria and viruses. A certain amount of chlorine is then left in the water that travels to your home to provide ongoing protection against contaminants. It can make your water taste and smell funny and can also irritate sensitive skin. You may also notice a burning sensation when you breathe in the steam from your shower if your water has chlorine left in it.

  • Disinfection by-products: Chlorine and chloramine can react with organic compounds already in the water and form what are known as “disinfection by-products.” Many of these are known to cause cancer.

  • VOCs and PFAs: Volatile organic compounds (VOCs) and per- and polyfluorinated substances (PFAs) are both the products of industrial runoff that dissolve in water. They can have a number of negative health impacts if found in high levels in your water. More common in city water due to the proximity to industrial facilities, they can be found in both city and well water.

  • Lead: If your home has old pipes or plumbing fixtures, you may have lead in your water. Prolonged lead exposure can cause all sorts of health problems and is especially dangerous to children.

  • Heavy metals: In addition to lead, other heavy metals, such as arsenic or copper, may get into your water supply.

  • Calcium and magnesium: Known as “hardness minerals” these do not pose a health risk, but they do cause scale buildup on your fixtures, leave marks on your dishes, prevent soap from lathering and make cleaning harder, and can irritate sensitive skin. 

If a filter claims to be an effective solution for city water, it must have technologies in place to deal with most of these contaminants. 

One exception is calcium and magnesium. It’s only necessary to address these contaminants if you actually have hard water. Lead is also not always required, as it’s not common and is only a concern if your water test results reveal you do, in fact, have lead in your water. 

During this part of the process, we are also on the lookout for products promising to do too much. If a product is designed for city water but comes equipped with products that deal with common well water contaminants, this is likely just artificially raising the price and is something we want to avoid.

Common Contaminants in Well Water

The idea of well water is appealing to many homeowners. Water pulled from the ground gives the impression of being “cleaner” and “healthier.” But this is not always the case. 

According to Johnny Pujol, a water quality engineer at Tap Score, another of our trusted partners, “It’s important to understand that many harmful contaminants occur naturally in the earth’s crust, so well water — sometimes described as “artisanal” or “spring” water — is not pure by definition. Nearby contamination from agriculture, heavy industry and other activities can also affect water safety.”

Every well is different, so the list of potential contaminants is quite large. Here are some of the most common:

  • Sediment: Dirt, dust, sand, silt, clay, and more can get into your water supply. In addition to making your water look and taste funny, sediment can also clog faucet aerators, washing machine screens, dishwashers, and other appliances that used water, including filters.

  • Iron: Dissolved iron is invisible, but it leaves red stains on anything your water touches: sinks, tubs, shower stalls, driveways, foundations, laundry, etc. It’s not a serious health hazard, but it’s a major pain in the neck. If iron is visible, it has already oxidized and is called rust. It will look like sediment in your water and needs to be filtered out.

  • Sulfur: Hydrogen sulfide in your water is what makes some well water smell like rotten eggs. In very high concentrations it can be toxic, but this is quite rare. It’s more often an unpleasant nuisance.

  • Manganese: Like iron, it’s not harmful to consume but manganese can leave black stains anywhere your water goes.

  • Herbicides, pesticides, and nitrates: If you live in an agricultural area, rain runoff can cause these chemicals to seep into groundwater supplies and your personal water supply.

  • Industrial runoff: Nearby factories or construction sites can also release all sorts of chemicals that drain into underground water supplies.

  • Bacteria and viruses: Your well is sealed off from the outside with a well cap. But if this is broken (very common), all sorts of organic matter can make its way into your water. If bacteria or viruses are allowed to grow inside your well and get into your water supply, it can make you and your family very ill. Many well caps are also underneath the soil line, which lets all sorts of stuff in your water and makes it hard to know when there is a problem.

  • Fluoride: Many cities add fluoride to your water to help with public dental health. But natural fluoride does exist and can be toxic at high concentrations.

  • Calcium and magnesium: Well water is very often also “hard water.” Similar to hard city water, this is not a health risk, but it can cause all sorts of annoyance, e.g., scale buildup, streaks and stains, poor soap performance, and skin irritation. 

If you have a private well and you come to us looking for a filter, the first thing we’re going to recommend is that you test your water. As you can see, there are a number of different things that could be in there, and we didn’t even list them all. 

This is also why this is the first step in our water filter review process. We can’t recommend products simply because they are advertised as “well filters.” We need to first verify what they are actually going to filter, and this allows us to separate products into different categories so that we can properly evaluate them and determine if they are worth your time and money.

Reviews You Can Count On

As part of our rigorous product research and testing methodology, we look at every aspect of buying and owning a water filtration system. The first step is to do a thorough use analysis to sort options into appropriate categories. But this is just one of many important factors we consider as we create product reviews you can count on.